Homework 4

javali_tests/HW4_nop90/Assignments/OkArraySubtypes.javali

@@ -0,0 +1,14 @@
+// any array is a subtype of Object
+// assignment and 'is equal' with an object of type 'Object' is fine
+
+class Main {
+	void main() {
+		boolean y;
+		Object x;
+		int[] testArray;
+		testArray = new int[10];
+		x = testArray;
+		testArray = null;
+		x = null;
+	}
+}

javali_tests/HW4_nop90/Assignments/OkSubtypes.javali

@@ -0,0 +1,21 @@
+// assignment of subtypes
+
+class Main {
+	void main() {
+		A a1, a2;
+		B b1, b2;
+		C c;
+		a1 = new A();
+		b2 = new B();
+		c = new C();
+		a2 = a1;
+		b1 = c;
+		
+	}
+}
+
+class A {}
+
+class B extends A {}
+
+class C extends B {}